Wow. It’s hard to believe this column marks the start of my tenth year withFloor Covering Installermagazine. The late Howard Olansky named the column “Let’s Talk Resilient” and my first column, “Concrete Moisture Problems: Causes and Detection” was published in the October 2003 issue.  It’s been an honor to be a part of this very well-regarded publication, and I especially appreciate the input and questions I receive from you, our readers, and from a variety of other sources. I’ve had a few more questions come in during the weeks before I started writing this month’s column, so the timing is perfect for some Q&A!

Q (From a distributor):I have an issue with a dealer who has had a problem where magic marker on the floor has bled through a heterogeneous sheet vinyl. Our position is, “Of course it would, and by not cleaning the marker off the floor, you are in breach of ASTM F710, section 4.2.” His response is he hasn’t had this problem with homogeneous sheet goods, and it is a problem unique to our material. Now I can see where the homogeneous material may be a little more resistant to the bleed through, but he had had more luck than anything if this didn’t happen previously.

A:I love it when someone references F 710 Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring*.  I have chaired the ASTM Task Group with jurisdiction over that document since 1996 and many fine people have volunteered countless hours to work on it. When someone actually references it, it makes our efforts worth it! The purpose of an industry standard is to set minimum standards for specifiers, manufacturers, users and installers to follow in order to assure that no resilient floor installation is affected by problems like this.

In this specific case, oil-based products like magic marker, pipe cutting oil and cutback adhesive (to name a few) can affect resilient flooring products in a variety of ways. This includes loss of adhesive bond due to chemical reaction, discoloration of the flooring material and a number of other potential problems. With regard to discoloration, some products might be almost immune from these problems and others may be more susceptible. But there is no way to predict when these problems may or may not occur, which is why, feeling this was an important issue, ASTM included language in the document in two different sections of F 710:

4.2 The surface of concrete floors to receive resilient flooring shall be dry, clean, smooth, and structurally sound. They shall be free of dust, solvent, paint, wax, oil, grease, residual adhesive, adhesive removers, film-forming curing compounds, silicate penetrating curing compounds, sealing, hardening, or parting compounds, alkaline salts, excessive carbonation or laitence, mold, mildew, and other foreign materials that might affect the rate of moisture dissipation from the concrete, the adhesion of resilient flooring to the concrete or cause a discoloration of the flooring from below.

7.1 The resilient flooring manufacturer shall be consulted regarding the necessity of removal of old resilient flooring, adhesive residue, paint, or other surface contaminants.*

Q (From a reader):My street was recently flooded, with the water level up above the crawl space of my 1900 house. All of the floor joists and the insulation between are somewhat wet. What is the best type of product to use to re-insulate? The floors are mostly old pine tongue-and-grove, w/ tile in powder room and laundry. Any special advice?

A:This is a little out of my area of expertise. However, I did spend 16 years as a volunteer and instructor for the IICRC as part of their Resilient Floor Inspector (RFI) and Substrate/Subfloor Inspector (ISSI) Certifications. During that time I got to know some of the experts that were involved in the Water Damage Restoration (WRT) and Applied Structural Drying (ASD) certifications and they are a great source of information. Contact

Q:Our church just bought a new building that used to be a library and was built in 1965.   In one area there are 9” x 9” tiles from the original construction that we were told contained asbestos. Can we take them up ourselves? What about the 12” x 12” tiles in the other area, which were installed in the 1980s? The same person told us only 9” x 9” tiles had asbestos, and that nothing after 1978 contained asbestos anyway.

A:This question continues to come up, and there is a lot of misunderstanding about asbestos in floor coverings. The federal law mandating that asbestos be removed from building materials was passed in the late 1970s, but gave the industry some time to work through their inventories by stating “Manufacture, importation and processing must cease by August 27, 1990” and “The ban on distribution in commerce ... will become effective on August 25, 1992”**.

Most manufacturers stopped using asbestos in floor coverings well before this date, but it was still legal to sell them so when dealing with a floor installed in 1993 or before, there is a chance that it contains asbestos. Assume it does unless it is tested. Both 9” x 9” and 12” x 12” products may have contained asbestos (as did some sheet goods and black adhesive). Don’t make that assumption it was only 9” tile.

When considering the removal of an existing floor, be sure it is legal for you to do so in your area – it may require a licensed Asbestos Abatement Contractor. You should also get a copy of Recommended Work Practices for Removal of Resilient Floor Coverings from the Resilient Floor Covering Institute (RFCI),*** which contains instructions for proper removal and the following statement:

Warning — Do not sand, dry sweep, dry scrape, drill, saw, beadblast, or mechanically chip or pulverize existing resilient flooring, backing, lining felt, paint, asphaltic cutback adhesives or other adhesives. These products may contain asbestos fibers or crystalline silica. Avoid creating dust. Inhalation of such dust is a cancer and respiratory tract hazard. Smoking by individuals exposed to asbestos fibers greatly increases the risk of serious bodily harm. Unless positively certain that the product is a non-asbestos-containing material, presume that it contains asbestos. Regulations may require that the material be tested to determine asbestos content. The Resilient Floor Covering Institute’s (RFCI’s) recommended work practices for removal of existing resilient floor coverings should be consulted for a defined set of instructions addressed to the task of removing all resilient floor covering structures.

Q:The architect specified plywood underlayment over concrete for a resilient floor project.  I read your column warning against doing that. What’s the problem?

A:The concern is that any moisture emissions from the concrete may cause the plywood to swell. Even a small amount of swelling may cause the joints and the fasteners to telegraph through the resilient flooring.

Q:I am trying to clarify what the moisture levels can be for the resilient floor I have to install. Some manufacturers list the calcium chloride test at “5 pounds” and some list the “RH test” at 75%.  Is there a correlation between the two?

A:This could be a whole column in and of itself so I’d first refer you to my March 2012 FCIcolumn, Concrete 101: Basics of Concrete and Moisture Testing, which went into a lot of detail on this subject. The short answer to your question is “No.” The Calcium Chloride Test (ASTM F 1869*) and the relative Humidity Test (ASTM F 2170*) measure different things.

F 1869 measures vapor emissions from the top surface of the concrete, about 3/4” down. That means the concrete could still be quite damp below that and this test would not detect that moisture. Since moisture moves up and concrete usually dries from the top down, the F 2170 method was developed to measure moisture in the form of relative humidity at 40% down in the slab. This is thought to be a better predictor of the long-term moisture movement in a slab.

There is value in doing both tests.  For example, a high reading on the F 1869 test and a passing F 2170 result may indicate the slab got flooded and needs to be dried out at the surface. If the results are reversed, the slab is drying from the top down and hasn’t fully dried yet. However, some suppliers are still behind the times and referencing the F 1869 Calcium Chloride test only, or they haven’t updated their literature, or you may have an old installation guide. Of course, “by the book” you should do the test that is recommended, but if only the F 1869 test is listed, call the supplier and ask them to clarify which method they would prefer, get them to send you their recommendations in writing, and keep that document with the file for the job. I’d recommend always doing the F 2170 test.  The new equipment out there makes it easier than ever.

Q:I am working on a “full spread” sheet resilient installation where a strip hardwood floor is currently installed. The owner doesn’t want to have plywood installed over the wood floor and asked if I could just sand it smooth instead. What are the risks of doing it this way?

A:“Full Spread” resilient floors are completely glued down, as opposed to a perimeter adhered floor or a “loose lay.” That means they will “telegraph” just about any imperfection there is in the existing substrate. My dad used to say, “Don’t leave a business card behind” when installing smooth surface sheet goods because even that little of an imperfection could show through. I never tested his theory but the point is well taken -  you are only as good as what you cover.

In the case of a strip wood floor, sanding it smooth may give a nice smooth substrate before the floor is installed, but the nature of wood is that it expands and contracts with changes in temperature and humidity. Even the moisture from the adhesive may be enough to cause boards to swell, and that would be visible through the new floor.

ASTM F 1482, Standard Practice for Installation and preparation of Panel Type Underlayments to Receive Resilient Flooring covers this point as follows:“If the strip wood is 3” or less in width and is tongue and groove with a smooth surface, use a minimum 1/4” approved panel underlayment to reduce the potential of board telegraphing. For boards wider than 3”, use 1/2” minimum …”

Thanks again for all of your questions, and please keep them coming. Your feedback is always appreciated!


* ASTM Standards available from ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA, 19428-2959 USA.


**Federal register Part III Environmental Protection Agency 40 CFR Part 763 Asbestos: Manufacture, Importation, Processing, and Distribution in Commerce Prohibition; Final Rule – July 12 1989.


*** Resilient Floor Covering Institute 115 Broad Street Suite 201, LaGrange, Georgia 30240 706-882-3833